<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button class="btn1">click</button>
    <script>
        let name_ = '阿黄';
        let obj1 = {
            name_: 'ergou',
            sayname_1: function() {
                console.log(this);
                return ()=>{
                    console.log(this.name_);
                }
            },
            sayname_2: ()=>{
                console.log(this);
                return ()=>{
                    console.log(this.name_);
                }
            }
        }

        let fn1 = obj1.sayname_1();
        let fn2 = obj1.sayname_2();

        document.querySelector('.btn1').onclick = function() {
            console.log(this);
        }
        document.querySelector('.btn1').onclick = ()=>{
            console.log(this);
        }
    </script>
</body>
</html>